561
FXUS66 KMFR 191048
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
348 AM PDT Wed Mar 19 2025

.DISCUSSION...A passing upper ridge is starting today off with a
brief period of stable conditions ahead of an approaching impactful
cold front. Southerly gusty winds will start to develop late this
morning, especially along the Oregon coast and in the Shasta Valley.
Wind gusts of 60 to 70 mph are forecast for the coastal headlands
and the Shasta Valley. Gusty winds are expected to reach into the
southern Rogue Valley and across east side terrain this afternoon.
Please see NPWMFR for existing High Wind Warnings (Coastal areas,
Shasta Valley) and Wind Advisories (Southern Rogue Valley, east side
terrain). Winds in these areas may be capable of breaking tree
branches, which could fall on electric lines and affect power
availability. Travel may be difficult in these areas, especially
for high profile vehicles. Winds fall below hazard product
thresholds later this evening, although winds of 20-35 mph continue
over area terrain into Thursday.

Today`s front will also bring another round of precipitation across
the area. Snow levels will start at 4500-500 feet this afternoon,
lowering to 2500-3000 feet as the cold air mass moves over the area.
Western Siskiyou County and the Cascades are expected to see a
combination of gusty winds and significant snowfall this afternoon
through Thursday evening, with snowfall in the Cascades starting
later in the afternoon today. Western Siskiyou peaks and ridgelines
could get 6 to 12 inches of snow, while higher elevation portions
of the Cascades could see 7 to 14 inches of snowfall through
Thursday morning. Snowfall rates of 1 inch/hour are possible over
western Siskiyou County (80-90+% chances) and the Cascades (50-70%
chances) for brief periods on Wednesday evening. The combination of
moderate to heavy snowfall and gusty winds supports a Winter Weather
Advisories for elevations above 5000 feet in these areas from this
afternoon to Thursday afternoon.

Outside of these hazards, typical frontal conditions are expected.
Lower elevation areas in Curry County could see 0.5 to 1.0 inches of
rain, while coastal mountains could approach 2 inches of rainfall.
Areas north of Cape Blanco and in the Illinois Valley are forecast
to get about half an inch of rainfall, while the Rogue and Umpqua
valley floors are forecast to get 0.1 to 0.2 inches of rainfall.
Areas around Mount Shasta and most floors east of the Cascades are
expected to get less than an inch of snow, while areas north of
Chiloquin could get 1 to 2 inches of snowfall. East side peaks could
get up to 5 inches of snowfall. Precipitation is heaviest Wednesday
afternoon and evening, with post-frontal showers continuing through
Thursday morning.

On Thursday afternoon, another front looks to move over the area.
Showers continue behind that front through Friday and Saturday with
westerly flow continuing aloft. While precipitable water amounts
look higher with Thursday`s front than with Wednesday`s, a weaker
front and higher snow levels are making this front look less
impactful. Rainfall amounts west of the Cascades look similar to
today`s front, while 5000-5500 feet snow levels will reduce snowfall
amounts. Steady snowfall looks possible over the Cascades through
Friday and Saturday, with 8 to 12 inches of snowfall possible across
those two days.

Beyond Saturday, there`s good agreement in guidance that an upper
ridge will set up over the western United States. Temperatures will
warm quickly across the area early next week. Morning fog may be a
concern in low-elevation areas depending on lingering moisture.
Meteogram guidance for both the GFS and ECMWF suggest active weather
returning near the end of next week. -TAD

&&

.AVIATION...19/12Z TAFs...LIFR in the Umpqua Valley, including
Roseburg, is the current exception to VFR. Upper level clouds are
increasing ahead of a very strong front that will weaken slightly as
it moves inland late today into tonight. Southerly winds will
increase this morning, and mix out the Umpqua Valley stratus.

Strong, gusty winds today will peak in the afternoon and early
evening. Gusts of 25 to 35 kt are expected to affect area terminals.
Areas along the coast, may see a period of stronger gusts up to 60
mph as this front pushes onshore.

Isolated thunderstorms are possible over the coastal waters during
the afternoon and evening, particularly from around 21-03Z.
Inland, some areas may also see strong, gusty winds up to 60 mph
with best chances in the Shasta Valley, including near Montague.
MVFR conditions will develop along the coast late this afternoon as
rain moves onshore. Then, areas of MVFR and local IFR will spread
inland early this evening. Widespread mountain obscurations are
likely from late afternoon into tonight. -DW

&&

.MARINE...Updated 200 AM Wednesday, March 19, 2025...Southerly
winds will build to a peak this afternoon ahead of a very strong
front. Steep seas become very steep this morning with gale to storm
force winds developing. The storm force winds are expected for areas
within 30 nm of shore while gales are expected to continue beyond 30
nm from shore. Guidance indicates about a 10-20% chances for
thunderstorms over the waters late this afternoon through this
evening as well.

Winds ease this evening, though very steep seas will continue into
Thursday morning. Steep seas and Advisory strength southerly winds
follow Thursday, at least into Friday night with another weaker but
slower moving front. The strongest winds and steepest seas will
likely occur north of Cape Blanco.

Swell dominated seas are forecast to nudge slightly higher Saturday,
then lower on Sunday. A ridge with near shore thermal trough
develops later Sunday with dry weather and winds shifting to the
north. This may produce steep seas late Monday into Tuesday. -DW

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Winter Weather Advisory from 3 PM this afternoon to 11 AM PDT
     Thursday for ORZ027-028.

     High Wind Warning from 8 AM this morning to 8 PM PDT this
     evening for ORZ021-022.

     Wind Advisory from 11 AM this morning to 8 PM PDT this evening
     for ORZ026-029>031.

CA...Winter Weather Advisory from 3 PM this afternoon to 11 AM PDT
     Thursday for CAZ080.

     High Wind Warning from 8 AM this morning to 8 PM PDT this
     evening for CAZ081.

     Wind Advisory from 11 AM this morning to 8 PM PDT this evening
     for CAZ084-085.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT early
     this morning for PZZ350-356-370-376.

     Gale Warning until 11 AM PDT this morning for PZZ350-356-370-
     376.

     Storm Warning from 11 AM this morning to 5 PM PDT this afternoon
     for PZZ350-356-370-376.

     Hazardous Seas Warning from 5 PM this afternoon to 8 AM PDT
     Thursday for PZZ350-356-370-376.

&&

$$

TAD/DW/TAD